m16 R2, force-shutdown removes bootloaders

I dual boot Windows and Linux on my laptop. Occasionally, I need to force it to power off by holding the power button for 15 seconds. However, sometimes, upon starting again, the power button blinks blue twice (no red) and boots into either Windows or the SupportAssist recovery tool. Going into the BIOS shows that GRUB has been completely removed from the boot list. All files are intact, but I need to re-add the boot option. Is there some auto-recovery setting that's confused because I'm using unsupported by Dell Linux?